1. Field of the Invention
The present invention relates to a wrench adaptor allowing reversible operation. In particular, the present invention relates to a wrench adaptor that can be mounted to a box end of a wrench so as to engage with a socket while allowing reversible operation of the wrench.
2. Description of the Related Art
FIG. 7 of the drawings illustrates a conventional socket wrench 1a including a handle 11a and a head 12a having a compartment 121a. An annular groove 1211a is defined in an inner periphery defining the compartment 121a for receiving a C-clip 3a. The C-clip 3a includes plural protrusions 31a on an inner periphery thereof for engaging with an outer periphery 21a of a socket 2a received in the compartment 121a of the head 12a. The socket 2a is thus directly held in the head 12a. However, the wrench 1a can only be used with sockets 2a having a hexagonal outer periphery 21a. Namely, the wrench 1a cannot be used with sockets having a circular outer periphery. In addition, when using the sockets 2a with a conventional ring spanner, the latter can be used for driving a fastener in a single direction; namely, reversible operation cannot be obtained.
FIG. 8 illustrates a conventional combination wrench 3b having a box end. An adaptor 1b is coupled with the box end so as to engage with a socket 2b. The adaptor 1b includes a pawl section 17b that is configured complimentary to corners 32b of an inner periphery defining a hole 31b of the box end. The adaptor 1b further includes a flange 12b and a positioning member 18b respectively abutting against an upper edge and a bottom edge of the box end, thereby retaining the box end in place. A switch member 141b is provided on top of the adaptor 1b to allow switching in the ratcheting direction. However, the adaptor 1b can only be used with combination wrenches of special types having specific corners 32b. In a case that the comers 32b of the box end of the wrench are not configured complimentary to the pawl section 17b, the latter would slide easily relative to the former. In addition, switching by means of turning the switch member 141b cannot be easily achieved with a single hand. Further, the positioning member 18b could not provide a sufficient retaining force for retaining the adaptor in place.
An object of the present invention is to provide a wrench adaptor that can be mounted to a box end of a wrench so as to engage with a socket while allowing reversible operation of the wrench.
In accordance with the present invention, an adaptor is provided for engaging with a box end of a wrench for use with a socket. The adaptor comprises a housing, a body, a pawl, a biasing means, and a switch member. The housing includes a first end and a second end for engaging with a socket. The first end of the housing includes a compartment defined by a toothed inner periphery. The body includes a first end to be engaged in a box end of a wrench and a second end rotatably received in the compartment of the housing. The body includes a transverse groove, a bottom wall defining the transverse groove including a cavity. A pawl is pivotally mounted in the transverse groove and includes a first toothed side and a second toothed side selectively engaged with the toothed inner periphery of the housing. The biasing means is mounted in the cavity of the body for biasing the pawl toward the toothed inner periphery of the housing, thereby allowing one of the first toothed side and the second toothed side of the pawl to engage with the toothed inner periphery of the housing. A switch member includes a first end for manual operation and a second end engaged with the pawl. The switch member is pivotable between two positions corresponding to two opposite ratcheting directions to selectively urge an associated one of the first toothed side and the second toothed side of the pawl to engage with the toothed inner periphery of the housing.